Isotopes of tellurium

There are 39 known isotopes and 17 nuclear isomers of tellurium (₅₂Te), with atomic masses that range from 104 to 142. These are listed in the table below.

Isotopes of tellurium (₅₂Te)

Main isotopes[1] Decay abun­dance half-life (t1/2) mode pro­duct 120Te 0.09% stable 121Te synth 16.78 d ε 121Sb 122Te 2.55% stable 123Te 0.89% stable[2] 124Te 4.74% stable 125Te 7.07% stable 126Te 18.8% stable 127Te synth 9.35 h β− 127I 128Te 31.7% 2.2×1024 y β−β− 128Xe 129Te synth 69.6 min β− 129I 130Te 34.1% 7.91×1020 y β−β− 130Xe
Standard atomic weight Ar°(Te)
	127.60±0.03[3] 127.60±0.03 (abridged)[4]
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Naturally-occurring tellurium on Earth consists of eight isotopes. Two of these have been found to be radioactive: ¹²⁸Te and ¹³⁰Te undergo double beta decay with half-lives of, respectively, 2.2×10²⁴ (2.2 septillion) years (the longest half-life of all nuclides proven to be radioactive)^[5] and 8.2×10²⁰ (820 quintillion) years. The longest-lived artificial radioisotope of tellurium is ¹²¹Te with a half-life of about 19 days. Several nuclear isomers have longer half-lives, the longest being ^121mTe with a half-life of 154 days.

The very-long-lived radioisotopes ¹²⁸Te and ¹³⁰Te are the two most common isotopes of tellurium. Of elements with at least one stable isotope, only indium and rhenium likewise have a radioisotope in greater abundance than a stable one.

It has been claimed that electron capture of ¹²³Te was observed, but more recent measurements of the same team have disproved this.^[6] The half-life of ¹²³Te is longer than 9.2 × 10¹⁶ years, and probably much longer.^[6]

¹²⁴Te can be used as a starting material in the production of radionuclides by a cyclotron or other particle accelerators. Some common radionuclides that can be produced from tellurium-124 are iodine-123 and iodine-124.

The short-lived isotope ¹³⁵Te (half-life 19 seconds) is produced as a fission product in nuclear reactors. It decays, via two beta decays, to ¹³⁵Xe, the most powerful known neutron absorber, and the cause of the iodine pit phenomenon.

With the exception of beryllium, tellurium is the second lightest element observed to have isotopes capable of undergoing alpha decay, with isotopes ¹⁰⁴Te to ¹⁰⁹Te being seen to undergo this mode of decay. Some lighter elements, namely those in the vicinity of ⁸Be, have isotopes with delayed alpha emission (following proton or beta emission) as a rare branch.

List of isotopes

Nuclide [n 1]	Z	N	Isotopic mass (Da)[7] [n 2][n 3]	Half-life[1] [n 4][n 5]	Decay mode[1] [n 6]	Daughter isotope [n 7]	Spin and parity[1] [n 8][n 5]	Natural abundance (mole fraction)
	Excitation energy							Normal proportion[1]	Range of variation
104Te	52	52	103.94672(34)	<4 ns	α	100Sn	0+
105Te	52	53	104.94330(32)	633(66) ns	α	101Sn	(7/2+)
106Te	52	54	105.93750(11)	78(11) μs	α	102Sn	0+
107Te	52	55	106.93488(11)#	3.22(9) ms	α (70%)	103Sn	5/2+#
					β+ (30%)	107Sb
108Te	52	56	107.9293805(58)	2.1(1) s	α (49%)	104Sn	0+
					β+ (48.6%)	108Sb
					β+, p (2.4%)	107Sn
					β+, α (<0.065%)	104In
109Te	52	57	108.9273045(47)	4.4(2) s	β+ (86.7%)	109Sb	(5/2+)
					β+, p (9.4%)	108Sn
					α (3.9%)	105Sn
					β+, α (<0.0049%)	105In
110Te	52	58	109.9224581(71)	18.6(8) s	β+	110Sb	0+
111Te	52	59	110.9210006(69)	26.2(6) s	β+	111Sb	(5/2)+
					β+, p (?%)	110Sn
112Te	52	60	111.9167278(90)	2.0(2) min	β+	112Sb	0+
113Te	52	61	112.915891(30)	1.7(2) min	β+	113Sb	(7/2+)
114Te	52	62	113.912088(26)	15.2(7) min	β+	114Sb	0+
115Te	52	63	114.911902(30)	5.8(2) min	β+	115Sb	7/2+
115m1Te[n 9]	10(6) keV			6.7(4) min	β+	115Sb	(1/2+)
115m2Te	280.05(20) keV			7.5(2) μs	IT	115Te	11/2−
116Te	52	64	115.908466(26)	2.49(4) h	β+	116Sb	0+
117Te	52	65	116.908646(14)	62(2) min	EC (75%)	117Sb	1/2+
					β+	117Sb
117mTe	296.1(5) keV			103(3) ms	IT	117Te	(11/2−)
118Te	52	66	117.905860(20)	6.00(2) d	EC	118Sb	0+
119Te	52	67	118.9064057(78)	16.05(5) h	EC (97.94%)	119Sb	1/2+
					β+ (2.06%)	119Sb
119mTe	260.96(5) keV			4.70(4) d	EC (99.59%)	119Sb	11/2−
					β+ (0.41%)	119Sb
120Te	52	68	119.9040658(19)	Observationally Stable[n 10]			0+	9(1)×10−4
121Te	52	69	120.904945(28)	19.31(7) d	β+	121Sb	1/2+
121mTe	293.974(22) keV			164.7(5) d	IT (88.6%)	121Te	11/2−
					β+ (11.4%)	121Sb
122Te	52	70	121.9030447(15)	Stable			0+	0.0255(12)
123Te	52	71	122,9042710(15)	Observationally Stable[n 11]			1/2+	0.0089(3)
123mTe	247.47(4) keV			119.2(1) d	IT	123Te	11/2−
124Te	52	72	123.9028183(15)	Stable			0+	0.0474(14)
125Te[n 12]	52	73	124.9044312(15)	Stable			1/2+	0.0707(15)
125mTe	144.775(8) keV			57.40(15) d	IT	125Te	11/2−
126Te	52	74	125.9033121(15)	Stable			0+	0.1884(25)
127Te[n 12]	52	75	126.9052270(15)	9.35(7) h	β−	127I	3/2+
127mTe	88.23(7) keV			106.1(7) d	IT (97.86%)	127Te	11/2−
					β− (2.14%)	127I
128Te[n 12][n 13]	52	76	127.90446124(76)	2.25(9)×1024 y[n 14]	β−β−	128Xe	0+	0.3174(8)
128mTe	2790.8(3) keV			363(27) ns	IT	128Te	(10+)
129Te[n 12]	52	77	128.90659642(76)	69.6(3) min	β−	129I	3/2+
129mTe	105.51(3) keV			33.6(1) d	IT (64%)	129Te	11/2−
					β− (36%)	129I
130Te[n 12][n 13]	52	78	129.906222745(11)	7.91(21)×1020 y	β−β−	130Xe	0+	0.3408(62)
130m1Te	2146.41(4) keV			186(11) ns	IT	130Te	7−
130m2Te	2667.2(8) keV			1.90(8) μs	IT	130Te	(10+)
130m3Te	4373.9(9) keV			53(8) ns	IT	130Te	(15−)
131Te[n 12]	52	79	130.908522210(65)	25.0(1) min	β−	131I	3/2+
131m1Te	182.258(18) keV			32.48(11) h	β− (74.1%)	131I	11/2−
					IT (25.9%)	131Te
131m2Te	1940.0(4) keV			93(12) ms	IT	131Te	(23/2+)
132Te[n 12]	52	80	131.9085467(37)	3.204(13) d	β−	132I	0+
132m1Te	1774.80(9) keV			145(8) ns	IT	132Te	6+
132m2Te	1925.47(9) keV			28.5(9) μs	IT	132Te	7−
132m3Te	2723.3(8) keV			3.62(6) μs	IT	132Te	(10+)
133Te	52	81	132.9109633(22)	12.5(3) min	β−	133I	3/2+#
133m1Te	334.26(4) keV			55.4(4) min	β− (83.5%)	133I	(11/2−)
					IT (16.5%)	133Te
133m2Te	1610.4(5) keV			100(5) ns	IT	133Te	(19/2−)
134Te	52	82	133.9113964(29)	41.8(8) min	β−	134I	0+
134mTe	1691.34(16) keV			164.5(7) ns	IT	134Te	6+
135Te[n 15]	52	83	134.9165547(18)	19.0(2) s	β−	135I	(7/2−)
135mTe	1554.89(16) keV			511(20) ns	IT	135Te	(19/2−)
136Te	52	84	135.9201012(24)	17.63(9) s	β− (98.63%)	136I	0+
					β−, n (1.37%)	135I
137Te	52	85	136.9255994(23)	2.49(5) s	β− (97.06%)	137I	3/2−#
					β−, n (2.94%)	136I
138Te	52	86	137.9294725(41)	1.46(25) s	β− (95.20%)	138I	0+
					β−, n (4.80%)	137I
139Te	52	87	138.9353672(38)	724(81) ms	β−	139I	5/2−#
140Te	52	88	139.939487(15)	351(5) ms	β− (?%)	140I	0+
					β−, n (?%)	139I
141Te	52	89	140.94560(43)#	193(16) ms	β−	141I	5/2−#
142Te	52	90	141.95003(54)#	147(8) ms	β−	142I	0+
143Te	52	91	142.95649(54)#	120(8) ms	β−	143I	7/2+#
144Te	52	92	143.96112(32)#	93(60) ms	β−	144I	0+
145Te	52	93	144.96778(32)#	75# ms [>550 ns]	β−	145I
This table header & footer: view

1. ^mTe – Excited nuclear isomer.
2. ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. Bold half-life – nearly stable, half-life longer than age of universe.
5. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
6. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   n:	Neutron emission
   p:	Proton emission

7. Bold symbol as daughter – Daughter product is stable.
8. ( ) spin value – Indicates spin with weak assignment arguments.
9. Order of ground state and isomer is uncertain.
10. Believed to undergo β⁺β⁺ decay to ¹²⁰Sn with a half-life over 1.6×10²¹ years
11. Believed to undergo electron capture to ¹²³Sb with a half-life over 9.2×10¹⁶ years
12. Fission product
13. Primordial radionuclide
14. Longest measured half-life of any nuclide
15. Very short-lived fission product, responsible for the iodine pit as precursor of ¹³⁵Xe via ¹³⁵I

References

1. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
2. Alessandrello, A.; Arnaboldi, C.; Brofferio, C.; Capelli, S.; Cremonesi, O.; Fiorini, E.; Nucciotti, A.; Pavan, M.; Pessina, G.; Pirro, S.; Previtali, E.; Sisti, M.; Vanzini, M.; Zanotti, L.; Giuliani, A.; Pedretti, M.; Bucci, C.; Pobes, C. (2003). "New limits on naturally occurring electron capture of ¹²³Te". Physical Review C. 67: 014323. arXiv:hep-ex/0211015. Bibcode:2003PhRvC..67a4323A. doi:10.1103/PhysRevC.67.014323.
3. "Standard Atomic Weights: Tellurium". CIAAW. 1969.
4. Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
5. Many isotopes are expected to have longer half-lives, but decay has not yet been observed in these, allowing only a lower limit to be placed on their half-lives
6. A. Alessandrello; et al. (January 2003). "New Limits on Naturally Occurring Electron Capture of ¹²³Te". Physical Review C. 67 (1): 014323. arXiv:hep-ex/0211015. Bibcode:2003PhRvC..67a4323A. doi:10.1103/PhysRevC.67.014323. S2CID 119523039.
7. Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
• "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
  • Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F. (2017-01-01). "Measurement of the two-neutrino double-beta decay half-life of ¹³⁰Te with the CUORE-0 experiment". The European Physical Journal C. 77 (1): 13. arXiv:1609.01666. Bibcode:2017EPJC...77...13A. doi:10.1140/epjc/s10052-016-4498-6. ISSN 1434-6044. S2CID 254105128.